Commutator-brush holder.



No. 662,758. 4 Patented Nov. 27, I900. H. BISHOP.

GOMMUTATDR BRUSH HOLDER.

(Application filed July 8, 1900.)

(No Model.)

I'll-MIMI I WITNESSES: //v YEN 70/? UNITED STATES,

PATENT ()FFICE.

HARRY BISHOP, OF NEIV YORK, N. Y.

COMMUTATOR-BRUSH HOLDER.

SPECIFICATION forming part of Letters Patent No. 662,758, dated November27, 1900.

Application filed July 3, 1900. Eerial No. 22,453. (N0 ode T0 aZZ whomit may concern:

Be it known that I, HARRY BISHOP, a citizen of the United States, and aresident of the city of New York, borough of'Manhattan, in the countyand State of New York, have invented a new and Improved Oommutator-Brush Holder, of which the following is afull, clear, and exactdescription.

The object of the invention is to provide a new andimprovedcommutator-brush holder arranged to insure at all times a firm contactbetween the conducting-block and the commutator and the seat of saidblock and to allow a free sliding movement of the conducting-blockwithout danger of the block leaving its seat.

The invention consists of novel features and parts and combinations ofthe same, as will be fully described hereinafter and then pointed out inthe claims.

A practical embodiment of the invention is represented in theaccompanying drawings, forming a part of this specification, in whichsimilar characters of reference indicate corresponding parts in bothviews.

Figure l is a side elevation of the improvement as applied and with thecommutator shown in section, and Fig. 2 is a cross-section of the same.

In commutator-brush holders heretofore constructedforinstance, such asshown and described in the Letters Patent of the United States No.504,901, granted to R. N. Bayles on September 12, 1893-serious defectsexist, of which the most notable is that on the slightest roughnessappearing on the commutator the brush is lifted slightly from its seat,thus allowing the current to arc from the brush to the holder and causethe brush and holder to burn in spots, and when the brush falls backinto position it rides on these burned spots, thereby making a hadcontact with its seat, causing overheating of the parts affected and ina short time rendering the brush useless for further service, besidesheating the dynamo generally, burning the brush-holder and commutator,and requiring constant sandpapering and turning down at least threetimes as often as should be necessary. These defects naturally curtailthe life and usefulness of the entire machine. When the contact betweenthe brush and its seat becomes bad,then the pivot-lever now employed andengaging the brush for pushing the same in contact with the commutatorbecomes a conductor, and by carrying an excessive current the part incontact with the brush burns into the side of the brush, rendering thetake-up for wear on the brush inoperative. In order to overcome thesedefects, I provide a take-up or follower arranged to cause the brush tobe at all times in firm contact with its seat and with the commutatorand at the same time allow a free sliding of the brush on its seat, butholding the brush against movement from its seat.

As shown in Fig. 1, the commutator A is engaged by a conductor or brushin the form of a block B, of carbon or other electric conductor, andhaving a beveled end lying against said commutator. The block B isseated on the seat 0 of a holder 0, secured bysnitable means to theframe of the machine, and said holder carries a cylinder D, in which ismonnted to slide the slide or cross-head E, pressed toward the brush andconductor by a spring F, the tension of which can be regulated by ascrew-rod G, screwing in the cap D of the cylinder and locked in placeagainst accidental movement after adjustment is made by a jam-nut G. Theslide E is provided with projecting lugs E, extending through guideslotsD in the cylinder D to hold the slide from turning and to allow theoperator to take hold of the projecting ends of the lugs E and force theslide outward against the tension of the spring F whenever it is desiredto replace a worn-out brush B by a new one. The free end of the slide Eis forked, and a pivot-pin E is held in the fork members, and on thispivot-pin is fnlcrnmed a follower consisting, essentially, of an angularor bell-crank lever H, having transverse pins H H on opposite sides ofits fulcrum, friction-rollers H 'H being journaled on said pins andpreferably in pairs, the friction-rollers being located on oppositesides of the follower H, as plainly shown in Fig. 2. The friction-rollerH engages the upper end of the block B, while the other friction-rollerH engages the free face of the said block. As the spring F presses theslide E inward in a line parallel to the seat C and as thefriction-rollers H H engage the brush-block B at adjacent faces, it

is evident that the follower presses the block 13 toward the commutatorA by the action of the rollers H H and as the rollers have a fixedrelation to each other it is evident that when one recedes the otherfollows, and consequently a free sliding movement of the block B is hadon the seat 0, and at the same time the block is prevented from movingfrom the seat C.

By the construction described the two members of the follower bear onthe adjacent faces of the block B with approximately equal pressure,thereby rendering arcing between the brush and holder impossible and atthe same time remedying all the defects above mentioned, giving longerlife to the brush and commutator, and requiring less labor to operatethe dynamo and less power to drive it, owing to the saving in the amountof heating now going to waste. By the operator adjusting the screw-rod Gthe tension of the spring F is regulated to insure a uniform pressing ofthe brush-block against the commutator and its seat C.

The sets of rollers H andI-I make linecontact with the outer end andface of the brush, and thereby insure at all times a good contact evenif such end and face is more than ordinarily rough, and as the rollershave rolling contact with the ends and face referred toit is evidentthateven the slightestvibration of the brush causes turning of the rollerson the brush-surfaces Without, however, breale ing the contact, as amovement of the brush against one roller will cause the other roller tobear with a force against its brush-surface equal to that which thebrush exerts against the other roller. By the arrangement described aminute movement of the rollers on the brush-surfaces is caused by thevibrating motion of the brush; but a perfect contact is at all timesmaintained to prevent even the slightest break in the current.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent- 1. Acommntator-brushholderhavingafollowerpressing the conductor and consisting of an angular lever, and rollerson the ends of the lever on opposite sides of the levers fulcrum, therollers being arranged to engage one end and the outer face of theconductor to hold the latter against its seat and against thecommutator, and at the same time prevent movement of the conductor fromits seat.

2. A comm utator-brush holderhavinga follower, and a spring-pressedsupport on which the follower is fulcrumed, the follower comprising anangular lever and rollers on the ends of the lever, the rollers engagingone end. and the outer face of the brush or conductor, as set forth.

3. A commutator-brush having a springpressed movable support, an angularlever fulcrumed on said support, and rollers journaled on the ends ofthe lever on opposite sides of the fulcrum, one of the rollers engagingone end of the conductor and the other the outer face thereof, as setforth.

4. A comm utator-brush holder, comprising a holder having a seat for thebrush or conductor, a cylinder on said holder, a slide movable in saidcylinder and arranged to move approximately parallel to said seal, aspring for pressing said slide, means for adjusting the tension of saidspring, and a follower pivoted on said slide and having a plurality ofmembers for engaging and pressing adjacent faces of the brush, as setforth.

5. A commutator-brush holder, comprising a holder having a seat for thebrush or cond uctor, a cylinder on said holder, a slide movable in saidcylinder and arranged to move approximately parallel to said seat, aspring for pressing said slide, means for adjusting the tension of saidspring, a follower pivoted on said slide and having a plurality ofmembers for engaging and pressing adjacent faces of the brush, and lugsprojecting from the slide and extending through slots in said cylinder,to hold the slide against turning and to permit of manually moving theslide, as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

HARRY BISHOP.

Vitnesses:

JOEL S. DE SELnINe, CHARLES J. FISHER.

